Plywood panel construction



y 2, 1957 D. A. PROUDFOOT PLYWOOD PANEL CONSTRUCTION Filed May 8, 1964FIG. 2

FIG. 3

I30 M m mm W HOA INVENTOR DON A. PROUDFOOT 9' fir ATTORNEYS UnitedStates Patent 3,316,684 PLYWOOD PANEL CONSTRUCTION Don A. Proudfoot,Cedarwood Drive, Greenwich, Conn. 06830 Filed May 8, 1964, Ser. No.365,896 4 Claims. (Cl. 52--615) This invention relates to plywood panelconstructions, and more particularly to such constructions for interiorand decorative finish uses. It is principally concerned with theproblems attending the use of low grade wood veneers with stainedfinishes, for interior plywood panelling. Even more specifically, theinvention evolves around the use of comparatively, structurally weak,low grade veneers for interior plywood panel facing.

A prime example of a low-grade wood veneer, previously considered as fitonly for interior ply or crossbanding use is a very low-grade Douglasfir veneer, known as white-pocket veneer and so called because ofdepressions and holes in the veneer, the surfaces of which are white,the condition arising because of a fungus, Fom-es pini, which infects agood quantity of Douglas fir trees.

Previous attempts have been made to use white-pocket veneer as the facestock for interior plywood panels. These attempts have failed as it is apractical impossibility to obtain either rotary cut or slicedwhite-pocket veneer in commercial quantities with a uniform enough fieldof infestation over the face of a 4 x 8' sheet and between one sheet andanother. Furthermore, as rotary cut fir veneer is literally peeled fromlo-gs roughly parallel to the annual growth rings, it presents a mostunattractive facing material because of the great contrast in densityand appearance between spring and summer wood, resulting in wild andnon-uniform configurations of grain. Sliced veneer of the white-pocketvariety although presenting a better grain appearance, has still beenconsidered undesirable because of infestation non-uniformity.

Two further problems have kept low grade wood veneer of the white-pocketvariety from any appreciable use as interior plywood facing material.The first is that due to lower density characteristics of such veneers,as opposed to the higher grade woods, and due to the weakening of theveneer because of the fungus infestation, a panel with a facing of sucha veneer would be structurally unbalanced if merely replacing thenormally higher grade or uninfected facing with the lower grade infectedwood were attempted.

The second further problem which has kept low grade wood veneers of thewhite-pocket variety from use as interior plywood facing material arisesbecause of the usual veneer strip construction of plywood panels. Inlaying up plys of wood veneers, the better grades of wood yieldapproximately 6 to 20 inch width strips which are joined along theirsides to make up the normal four foot width of the standard 4' X 8'panel. White-pocket, in such widths presents an aggravated, undesirablepicture of non-uniform fungus infestation, knots and wild configurationsof grain. To merely use lesser width strips of the low grade veneerwould not solve the appearance problem appreciably as the use of eventhe selectively available 3 to 8 inch width strips, of white-pocket donot sufficiently minimize the infestation nonuniformity and undesirablegrain configurations. Furthermore the appearance of so many smallerwidth veneer strips as a facing creates its own unattractive results.

It is an object of the present invention to permit the use of low gradewood veneer as face stock by overcoming the appearance and structuralproblems just discussed.

In a practical embodiment of the invention there is provided adecorative plywood panel having a back ply of low grade but sound wood,a center ply of any acceptable grade and in accordance with theinvention, a stained facing ply comprised of comparatively narrow sideby side, edge joined veneer strips of low grade wood having commerciallyintolerable appearance and structural characteristics, such as wildgrain configuration, and in the case of white-pocket veneer, non-uniformfields of fungus infestation, the grain configurations and fields ofinfestation differing appreciably in each strip and from strip to strip.In .further accordance with the invention, strips of decorative andstructural media, preferably of a density and strength greater than thatof the facing veneer, and comparatively thin in thickness and sometimesin width relative to the facing veneer strips, are laid up on the facingveneer, preferably overlying the veneer joints from the top edge to thebottom edge of the panel.

The strip media, which can be made of metal, plastic, or any othermaterial compatible with the appearance and structural demands of thedecorative panelling, constructed .as described, accomplishes two aimswhen used in this environment. First it breaks up the unattractive grainand infestation patterns so that wildness and nonuniformity,respectively, are lost in the overriding design of finished, albeitinfested, wood sections alternating with strips of media having acontrasting design impact. Just as importantly, the addition of thestructurally stronger strips to the weakened facing of the infectedveneer, restores balance to the otherwise unbalanced panel so thatwarpage and other distortions due to hu .midity changes, for instance,which would seriously affect a panel having a weak face veneer on oneside and not on the other, are kept within acceptable tolerances.

In this last respect the invention contemplates that the material forthe strip media can be such that its dimensions will be relativelystable regardless of moisture content or environment. Thus, materialswhich are comparatively non-porous and non-absorbent of water are wellsuited for use as strip media.

The application of the strip media to may be by gluing and may take theform or inlay, either within into the veneer.

Because of the comparatively small widths of low grade veneer whichresults from selecting the stock to eliminate knotes, for instance, andto attain a reasonable degree of uniformity of pocketing, it isdesirable to lay up the strip media along the veneer joints to eliminatethe appearance of the joint and where larger widths occur over anyparticular veneer strip, a strip of the media may be placed intermediatethe edges for appearance or balancing purposes.

In carrying out the objects of the invention it has been found thatwhere metals are concerned, strip media made of copper metals areparticularly compatible with the structural and appearancecharacteristics of the invention. Copper, brass and bronze provide verydesirable architectural results. Other metals such .as aluminum are alsoconsidered quite compatible.

The above and further objects of the invention are deducible from thefollowing description of a specific embodiment thereof when taken inconjunction with the drawings, of which:

FIG. 1 is a perspective view of panel incorporating the invention;

FIG. 2 is a magnified, transverse section through a portion of the FIG.1 panel; and

FIG. 3 is a transverse sectional view of a pair of panels incorporatingthe invention and showing an edge joint between the two panels.

The plywood panel 10, shown in FIGS. 1 and 2 represents a one quarterinch, three-ply panel having a back ply 11 of low grade but uninfestedwood (which may be the facing veneer of face mounting pre-formedgrooves, or pressed an interior plywood grade D for instance), a crossband ply 12 which may be of any suitable grade, and a facing ply 13,made up of side by side and conventionally edged joined strips ISA-ilSAAof white-pocket Douglas fir, rotary cut veneer. The plys are gluedtogether in conventional fashion and, as is usual, the grain, not shown,except for grain configurations g in facing ply 1 3, in any one ply runsgenerally perpendicularly to the grain of each adjacent It should beunderstood that a panel having five or more plys can be readily adaptedto incorporate the invention so long as it includes the low grade facingveneer and strip media as described.

The fungus infection of the veneer strips 13A 1 3AA is shown by thepresence of depressions and holes 14 in the body of the consequentlyweakened veneer strips.

It can be appreciated that the areas of fungus infestation in the facingply 13 would, over wider areas, present an intolerable blotchyappearance in a panel made up only of edged joined facing veneer strips.

It can be appreciated too, that the wild grain configurations due to therotary cutting of the fir log parallel to the annual growth rings andthrough spring and summer wood, if carried through in larger widthareas, such as are available in uninfected wood veneers, would beextremely unattractive as indeed they are, though minimized, even in thesmaller, 38 inch width areas which are available, through selection, inwhite-pocket veneers.

Furthermore, the extra number of joints in a veneer facing of thewhite-pocket fir, resulting because of strip selection would result inanother impossible appearance characteristic in that too many veneerstrips, as against the normal number of strips required where 6-20 inchconventional strips of veneer are used, are apparent on the face of thepanel.

In order to overcome these appearance problems and in order to addstrength to the weakened, infested facing ply to restore balance betweenthe back and facing plys, the strip media of the invention is applied tothe facing ply.

As shown in the drawing, strips 13A include in their outer faces grooves15, pre-formed by sanding or routing at the veneer joints 16 andpenetrating the bodies of ad jacent veneer strips so that the stripmedia can straddle adjacent veneer strips and cover the veneer joints.

Grooves, such as 17 (FIG. 2) intermediate the edges of a comparativelywider veneer strip 13AA are provided to receive the strip media forappearance purposes or for structurally balancing the facing panel 13 asagainst the back panel 11.

In accordance with the invention, strips of metal 18 are inlaid withinthe pre-formed grooves 15, resulting in a design of laterally spacedparallel strips of alternating finished wood and metal. The facing ply13 is thereby strengthened and a most attractive design impact isprovided by the breaking up of the grain and infestation patterns in theveneer strips 13A-13AA with interspaced strips of metal.

The strips 18 are shown in the drawings to be fabricated of metal, andin practice, copper metals have been found to be structurally andarchitecturally very compatible with wood finishes. It can beappreciated, however, that many different metals, for instance,aluminum, can be used for the strip media.

Furthermore, the strip media need not be restricted to metals but shouldpreferably be fabricated of a material which is comparatively non-porousand non-absorbent of water, as well as structurally sounder than the lowgrade veneer strips 13A, so that it will not only add strength to thefacing ply for balancing purposes, but will also be such as not to besubject to dimensional changes due to changes in moisture environment.

It should also be understood that the strip media need not be inlaid ingroove b t m y be face mounted. The

structural and appearance advantages have also been obtained in thismanner.

In accordance with what particular materials are used for the stripmedia, the staining or other finishing of the wood can be done before orafter the laying up of the strip media, and the affixing of the mediaupon the facing ply or within the grooves can be accomplished by wellknown adhesives, the choice of which will depend upon whether metal, asshown, is used for the strip media or whether other types of materialsare used.

To facilitate the utilization of panels constructed in accordance withthe invention, it is contemplated that the side edges of such panels maybe provided with mating grooves to accommodate strip media at the edgejoint. Thus the design effects of the alternating wood and strip mediaare carried through from one panel to the next. Also a facile andundetectable edge joinder operation, in situ, with more permissiblealignment tolerances than is the case with conventional panels, ispermitted.

As can be seen in the FIG. 3 presentation, the edges of panels 101 and111 are provided with complementary L grooves 26 within the facing plys130 along their laterally joined edges at edge joint 25. The panel backplys 110, A are, for purposes of illustration, laid flush against studssuch as stud 27 and fixed in place via nails 28. The metal strip media30 at the edge joint is set in place via any of the well known adhesivesfor fixing metal to wood and can be of the pressure sensitive variety.

Now it should be understood that the invention provides a mostdecorative interior plywood panel which utilizes for its facing ply,extremely low grades of wood and even such structurally weakened gradesof wood as whitepocket, Douglas fir. Even though such facing material isstructurally weaker than the back ply of the panel, the inventionprovides for a balanced panel because of the fact that the strip mediaused adds strength to the facing ply. In this last respect, theinvention also contemplates the use of strengthening decorative stripmedia on both sides of a decorative panel in a custom situation whenboth sides are to be viewed.

It should be understood that although a specific embodiment of theinvention has been shown and described, the scope of the invention is tobe limited only by the scope of the appended claims.

What is claimed is:

1. A plywood panel for interior decorative use comprising a plurality ofplys including at least a back ply and a facing ply, said facing plybeing constituted by edge joined strips of a low grade wood veneer of astrength and appearance unsuited for use as a facing ply and having anouter surface, and strips of material of higher strength characteristicsthan said low grade wood veneer of said facing ply, said strips of saidmaterial being secured to said outer surface of said veneer strips ofsaid facing ply and strengthening said facing ply and improving theappearance thereof to render said low grade wood veneer suitable for useas a facing ply.

2. The plywood panel of claim 1 wherein grooves are formed in and extendonly partly into said facing ply at its outer surface and said strips ofsaid material are secured within said grooves.

3. The plywood panel of claim 2 wherein said grooves are formed alongthe joined edges of said veneer strips.

4. The plywood panel of claim 1 wherein said low grade wood veneer is ofthe white-pocket variety.

References Cited by the Examiner UNITED STATES PATENTS 2,090,529 8/1937Gram 52-622 X 2,253,667 8/1941 Warner 52622 X 2,315,967 4/1943 Knowlton161--36 X HARRISON R. MOSELEY, Primary Examiner.

P. M. CAUN, Assistant Examiner.

1. A PLYWOOD PANEL FOR INTERIOR DECORATIVE USE COMPRISING A PLURALITY OFPLYS INCLUDING AT LEAST A BACK PLY AND A FACING PLY, SAID FACING PLYBEING CONSTITUTED BY EDGE JOINED STRIPS OF A LOW GRADE WOOD VENEER OF ASTRENGTH AND APPEARANCE UNSUITED FOR USE AS A FACING PLY AND HAVING ANOUTER SURFACE, AND STRIPS OF MATERIAL OF HIGHER STRENGTH CHARACTERISTICSTHAN SAID LOWER GRADE WOOD VENEER OF SAID FACING PLY, SAID STRIPS OFSAID MATERIAL BEING SECURED TO SAID OUTER SURFACE OF SAID VENEER STRIPSOF SAID FACING PLY AND STRENGTHENING SAID FACING PLY AND IMPROVING THEAPPEARANCE THEREOF TO RENDER SAID LOW GRADE WOOD VENEER SUITABLE FOR USEAS A FACING PLY.